Putting agri-waste to agri-use

Pawanpreet Singh Dhillon

A biomass power plant is similar to a thermal power plant, but instead of coal, it uses green fuel. Agriculture waste — such as paddy and wheat straw, cotton stalks and leaves, which are left over after harvesting of the crop — comprise the natural fuel. This agri-waste is normally burnt in the open fields. As its volume is so much, it is not possible for the farmers to deal with it without incurring a considerable cost to ready their fields for sowing of the next crop. This is particularly true in the case of paddy straw in Punjab, which generates about 20 million tons of straw yearly, eventually burnt in the open fields. 

It results in soaring pollution levels in the state and the NCR as well in October-November. Debate and discussion ensue on various forums. The government authorities and the National Green Tribunal get into action to deal with the situation. Several schemes, for example happy seeder (a machine used  to sow wheat without burning paddy straw), have been put out, but their efficacy is still not obvious. One of the sure-shot ways to deal with this alarming problem is the setting up of biomass power plants, which only use paddy straw as fuel. 

One such plant can produce 15 MW of power per hour using biomass. It can also have a positive impact on rural economy, environment and employment opportunities in the area. Indirect employment can be generated by fuel collection, which entails collection of all types of fuels, ranging from leaves to stalks. 

This job is mostly done by entrepreneur farmers who already own tractors for their farm operations. Each baler requires about 20 people for a smooth operation. The bales are then stacked in the fuel yards and transferred to the plant on a daily basis.  These bales are then fed into the boiler through contracted labour, which is again local. Sixty per cent of the revenue generated from this plant should be pumped back in the local economy every month.

The impact of this plant on the local environment can be noted by analysing the remote sensing data of the area. To deal with the problem in the area where the generation of paddy straw is huge, such measures are a must. Another very important factor related to the environment is the soil fertility, which gets adversely affected when the fields are set on fire. However, if the straw is collected with balers, the soil does not lose its fertility and the microbes or soil bacteria don’t get destroyed as well. The process helps reduce the use of fertilizers, which otherwise is a lot. The burning of straw in a controlled environment like that of power plants releases minimal amounts of carbon into the atmosphere, as compared to open burning. 

In all, the alternative to stubble burning should soon become the preferred way to handle the problem.